content: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2012, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jfreechart/index.html
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
   * Other names may be trademarks of their respective owners.]
   *
   * -------------------------
   * KeyedValueComparator.java
   * -------------------------
   * (C) Copyright 2003-2012, by Object Refinery Limited.
   *
   * Original Author:  David Gilbert (for Object Refinery Limited);
   * Contributor(s):   -;
   *
   * Changes:
   * --------
   * 05-Mar-2003 : Version 1 (DG);
   * 27-Aug-2003 : Moved SortOrder from org.jfree.data --> org.jfree.util (DG);
   * 12-Jan-2005 : Added accessor methods (DG);
   * 17-Jun-2012 : Removed JCommon dependencies (DG);
   *
   */
  
  package org.jfree.data;
  
  import java.io.Serializable;
  import java.util.Comparator;
  import org.jfree.chart.util.ParamChecks;
  
  import org.jfree.chart.util.SortOrder;
  
  /**
   * A utility class that can compare and order two {@link KeyedValue} instances
   * and sort them into ascending or descending order by key or by value.
   */
  public class KeyedValueComparator implements Comparator<KeyedValue>, Serializable {
  
      /** The comparator type. */
      private KeyedValueComparatorType type;
  
      /** The sort order. */
      private SortOrder order;
  
      /**
       * Creates a new comparator.
       *
       * @param type  the type (<code>BY_KEY</code> or <code>BY_VALUE</code>,
       *              <code>null</code> not permitted).
       * @param order  the order (<code>null</code> not permitted).
       */
      public KeyedValueComparator(KeyedValueComparatorType type,
                                  SortOrder order) {
          ParamChecks.nullNotPermitted(type, "type");
          ParamChecks.nullNotPermitted(order, "order");
          this.type = type;
          this.order = order;
      }
  
      /**
       * Returns the type.
       *
       * @return The type (never <code>null</code>).
       */
      public KeyedValueComparatorType getType() {
          return this.type;
      }
  
      /**
       * Returns the sort order.
       *
       * @return The sort order (never <code>null</code>).
       */
      public SortOrder getOrder() {
          return this.order;
      }
  
      /**
       * Compares two {@link KeyedValue} instances and returns an
       * <code>int</code> that indicates the relative order of the two objects.
       *
       * @param kv1  object 1.
       * @param kv2  object 2.
       *
       * @return An int indicating the relative order of the objects.
       */
      @Override
      public int compare(KeyedValue kv1, KeyedValue kv2) {
  
          if (kv2 == null) {
              if (kv1 ==null) {
                  return 0;
              }
              return -1;
          }
          if (kv1 == null) {
              return 1;
          }
  
          int result;
  
          if (this.type == KeyedValueComparatorType.BY_KEY) {
              if (this.order.equals(SortOrder.ASCENDING)) {
                  result = kv1.getKey().compareTo(kv2.getKey());
              }
              else if (this.order.equals(SortOrder.DESCENDING)) {
                  result = kv2.getKey().compareTo(kv1.getKey());
              }
              else {
                  throw new IllegalArgumentException("Unrecognised sort order.");
              }
          }
          else if (this.type == KeyedValueComparatorType.BY_VALUE) {
              Number n1 = kv1.getValue();
              Number n2 = kv2.getValue();
              if (n2 == null) {
                  return -1;
              }
              if (n1 == null) {
                  return 1;
              }
              double d1 = n1.doubleValue();
              double d2 = n2.doubleValue();
              if (this.order.equals(SortOrder.ASCENDING)) {
                  if (d1 > d2) {
                      result = 1;
                  }
                  else if (d1 < d2) {
                      result = -1;
                  }
                  else {
                      result = 0;
                  }
              }
              else if (this.order.equals(SortOrder.DESCENDING)) {
                  if (d1 > d2) {
                      result = -1;
                  }
                  else if (d1 < d2) {
                      result = 1;
                  }
                  else {
                      result = 0;
                  }
              }
              else {
                  throw new IllegalArgumentException("Unrecognised sort order.");
              }
          }
          else {
              throw new IllegalArgumentException("Unrecognised type.");
          }
  
          return result;
      }
  
  }
  